Deep Brain Stimulation for Cervical Dystonia

This study will evaluate the effectiveness of deep brain stimulation (DBS) in treating primary generalized dystonia. Patients with dystonia have muscle spasms that cause uncontrolled twisting and repetitive movement or abnormal postures. Medical therapies are available, but not all patients get adequate relief from the abnormal movements or the pain associated with them. DBS is a surgical procedure that interrupts neuronal circuits in the Gpi and STN, areas of the basal ganglia of the brain that do not work correctly in patients with dystonia. The surgery results in decreased movement and therefore may lessen patients' symptoms and pain. Patients 7 years of age and older with generalized dystonia that does not respond to medical treatment may be eligible for this study. Candidates are screened with blood and urine tests, chest x-ray, and an electrocardiogram in patients 35 years of age or more. Participants undergo the following tests and procedures: * Magnetic resonance imaging. MRI uses a magnetic field and radio waves to produce images of the brain. The patient lies on a table that is moved into the scanner (a narrow cylinder), wearing earplugs to muffle loud knocking and thumping sounds that occur during the scanning process. The procedure usually lasts about 45 to 90 minutes, during which the patient is asked to lie still for up to 15 minutes at a time. * Transcranial magnetic stimulation. This procedure maps brain function. A wire coil is held on the scalp, and a brief electrical current is passed through the coil, creating a magnetic pulse that stimulates the brain. During the stimulation, the patient may be asked to tense certain muscles slightly or perform other simple actions. The stimulation may cause a twitch in muscles of the face, arm, or leg, and the patient may hear a click and feel a pulling sensation on the skin under the coil. During the stimulation, electrical activity of muscles is recorded with a computer, using electrodes attached to the sk